Assessing energy use and greenhouse gas emission savings from compact housing: a small-town case study

Effectively addressing today’s energy challenges requires advanced technologies along with policies that influence economic markets while advancing the public good.

Regional land use and transportation planning influences energy use and greenhouse gas (GHG) emissions in a number of ways, such as through its effect on vehicle miles travelled and the extension of municipal infrastructure to serve newly developed areas. Planning regulations also help to shape the density and form of residential development, which creates opportunities for energy savings, as more compact housing types (attached homes and apartments) use less energy, on average, than single-family detached units. This study uses micro-data from the US Department of Energy's Residential Energy Consumption survey to estimate future residential energy use for space heating and cooling in Virginia's 10 Census-designated metropolitan regions. It then calculates the effect of four residential development scenarios on that energy demand and resulting GHG emissions. Potential GHG emission reductions of approximately 23% are found between the most conservative and aggressive scenarios. The greatest potential energy savings are found in regions that currently have a relatively low share of compact housing types, particularly those that also have relatively cold winters compared to the state's other regions. These factors, along with the distribution of home heating fuels used (electric vs. natural gas), influence the extent of potential GHG emissions reductions.

Climate change poses substantial challenges to policy implementation and planning at scales ranging from local to global. This study examines the effectiveness and challenges of implementing climate change policy, particularly in local climate action planning and implementation in Japan, focusing on the transportation and land use planning fields. It specifically asks questions about the efficacy of local governments’ practices and efforts in realising national carbon reduction goals, measures taken by local governments, and hurdles in implementation experienced by them. The study found several significant challenges in which local governments tend to meet procedural requirements but leave substantial uncertainty in the efficacy of their local climate action planning and implementation. The article calls for more stringent regulations and mandates, more robust initiatives and guidance considering the diverse local conditions, combined with better coordination among the ministries, for more effective greenhouse gas (GHG) emissions reduction.

Power utility companies in the United Kingdom are using imported wood pellets from the southern region of the United States for electricity generation to meet the legally binding mandate of sourcing 15% of the nation’s total energy consumption from renewable sources by 2020. This study ascertains relative savings in greenhouse gas (GHG) emissions for a unit of electricity generated using imported wood pellet in the United Kingdom under 930 different scenarios: three woody feedstocks (logging residues, pulpwood, and logging residues and pulpwood combined), two forest management choices (intensive and non-intensive), 31 plantation rotation ages (year 10 to year 40 in steps of 1 year), and five power plant capacities (20–100 MW in steps of 20 MW). Relative savings in GHG emissions with respect to a unit of electricity derived from fossil fuels in the United Kingdom range between 50% and 68% depending upon the capacity of power plant and rotation age. Relative savings in GHG emissions increase with higher power plant capacity. GHG emissions related to wood pellet production and transatlantic shipment of wood pellets typically contribute about 48% and 31% of total GHG emissions, respectively. Overall, use of imported wood pellets for electricity generation could help in reducing the United Kingdom’s GHG emissions. We suggest that future research be directed to evaluation of the impacts of additional forest management practices, changing climate, and soil carbon on the overall savings in GHG emissions related to transatlantic wood pellet trade.

Problem: Basing local climate action plans on greenhouse gas (GHG) emissions inventories has become standard practice for communities that want to address the problem of climate change. Communities use GHG emissions inventories to develop policy despite the fact that there has been little theoretical work on the implications of the assumptions embedded within them. Purpose: We identify elements and assumptions in emissions inventories that have important policy implications for climate action plan formulation, aiming to help planners make informed, defensible choices, and to refine future GHG emissions inventory protocols and climate action planning methods. Methods: We conducted a content analysis of 30 city climate action plans selected as a stratified random sample. We collected data on 70 different factors and used summary and trend statements, typologies, and descriptive statistics to link our findings to our research questions. Results and conclusions: Climate action plans obviously vary in many details, but most contain all of the core GHG emissions elements suggested in common protocols. We found GHG emissions inventories to be technically accurate but found their reduction targets to fall short of international targets. We also found exogenous change and uncertainty to be unaccounted for in emissions forecasts and reduction targets. The plans generally do a poor job of linking mitigation actions to reduction targets. Takeaway for practice: GHG emissions inventories supporting climate action planning are reasonably standardized, but documentation of data and assumptions should be improved and GHG reduction targets should be justified. The effect of future changes that are beyond the direct control of the community plan should be accounted for in GHG emissions forecasts and reduction targets. Rapid anticipated population growth should be acknowledged and taken into account, both in GHG emissions forecasts and in setting reduction targets. Effects of mitigation may be difficult to predict reliably, yet can be partly offset by effective monitoring that evaluates progress and changes course when necessary. Research support: None.

Woody feedstocks will play an important role in meeting the total demand for biomass to generate electricity and produce ethanol in the United States. We analyzed 186 different scenarios (31 rotation ages (10 to 40 years in annual time steps); two types of forest management (intensive and nonintensive); and three feedstocks (logging residues only, pulpwood only, logging residues and pulpwood combined)) for ascertaining relative savings in greenhouse gas (GHG) emissions of two wood-based energy products (electricity and ethanol) on per unit land and per unit energy bases with respect to equivalent fossil fuel based energy products. Relative savings in GHG emissions were higher under intensive forest management compared with nonintensive forest management on a per unit land basis, whereas this situation reverses on a per unit energy basis. Combined use of pulpwood and logging residues saved the highest amount of GHG emissions on a per unit land basis, but on a per unit energy basis, relative GHG savings were similar to when only logging residues were used as a feedstock. Existing policies promoting bioenergy development in the United States only consider GHG savings on a per unit energy basis. A need exists to consider GHG savings on a per unit land basis as well to ensure efficient utilization of existing land resources to mitigate GHG emissions.

Mitigating Curtailment and Carbon Emissions through Load Migration between Data Centers

Life cycle energy consumption and GHG emission from pavement rehabilitation with different rolling resistance

Energy-related activities are a major contributor of greenhouse gas (GHG) emissions. A growing body of knowledge clearly depicts the links between human activities and climate change. Over the last century the burning of fossil fuels such as coal and oil and other human activities has released carbon dioxide (CO2) emissions and other heat-trapping GHG emissions into the atmosphere and thus increased the concentration of atmospheric CO2 emissions. The main human activities that emit CO2 emissions are (1) the combustion of fossil fuels to generate electricity, accounting for about 37% of total U.S. CO2 emissions and 31% of total U.S. GHG emissions in 2013, (2) the combustion of fossil fuels such as gasoline and diesel to transport people and goods, accounting for about 31% of total U.S. CO2 emissions and 26% of total U.S. GHG emissions in 2013, and (3) industrial processes such as the production and consumption of minerals and chemicals, accounting for about 15% of total U.S. CO2 emissions and 12% of total ...

Delaware’s (DE) Climate Action Plan lays out a pathway to reduce greenhouse gas (GHG) emissions by at least 26% by 2025 but does not consider soil-based GHG emissions from land conversions. Consequently, DE’s climate action plan fails to account for the contribution of emissions from ongoing land development economic activity to climate change. Source attribution (SA) is a special field within the science of climate change attribution, which can generate “documentary evidence” (e.g., GHG emissions inventory, etc.). The combination of remote sensing and soil information data analysis can identify the source attribution of GHG emissions from land conversions for DE. Traditional attribution science starts with climate impacts, which are then linked to source attribution of GHG emissions. The most urgent need is not only to detect climate change impacts, but also to detect and attribute sources of climate change impacts. This study used a different approach that quantified past soil GHG emissions which are then available to support impact attribution. Study results provide accurate and quantitative spatio-temporal source attribution for likely GHG emissions, which can be included in the DE’s climate action plan. Including the impact of land conversion on GHG emissions is critical to mitigating climate impacts, because without a more complete source attribution it is not possible to meet overall emission reduction goals. Furthermore, the increased climate change impacts from land conversions are in a feedback loop where climate change can increase the rates of GHG emissions as part of these conversions. This study provides a spatially explicit methodology that could be applied to attribute past, future, or potential GHG emission impacts from land conversions that can be included in DE’s GHGs inventory and climate impact assessment.

This synthesis describes the role of transit agencies in reducing greenhouse gas (GHG) emissions and catalogues the current practice of a sample of transit agencies. The purpose of this synthesis is to inform transit agencies on how their services and operations specifically impact GHG emissions from transportation. Transportation is one of the largest sources of GHG emissions in the United States. Policymakers, planners, and transportation agencies are increasingly considering how the transportation sector can reduce its GHG emissions. This goal presents a complex challenge with no one single solution for transit agencies. They can contribute to this goal by increasing total ridership, boosting the numbers of passengers on individual trips, and reducing their use of energy from fossil-based sources. However, planning for and implementing strategies to reduce GHG emissions are still developing scenarios in the transit industry. Many transit agencies are struggling with how a goal to reduce GHG emissions can fit with their traditional planning objectives. Research for this study included a literature review, a survey of 41 transit agencies (66% response rate), and interviews with three agencies.

The United States Department of Energy’s Pacific Northwest National Laboratory is teaming with industry to deploy and independently monitor 5-kilowatt-electric (kWe) combined heat and power (CHP) fuel cell systems (FCSs) in light commercial buildings. Results of an independent evaluation of manufacturer-stated engineering, economic, and environmental performance of these CHP FCSs are presented here. An important contribution of this paper is the precise definition and development of these essential terms for quantifying distributed CHP generator energy use within buildings: (1) electricity and heat utilization, (2) electrical and heat recovery efficiencies, (3) in-use electrical and heat recovery efficiencies, (4) percentage usage of electricity, and (5) percent usage of recoverable heat. Key additional parameters evaluated include the average cost of the CHP FCSs per unit of power and per unit of energy, the change in greenhouse gas (GHG) and air pollution emissions with a switch from conventional power plants and furnaces to CHP FCSs, the change in GHG mitigation costs from the switch, and the change in human health costs from air pollution. CHP FCS heat utilization is expected to be under 100% at several installation sites; for six sites, during periods of minimum heating demand, the in-use CHP FCS heat recovery (HR) efficiency based on the higher heating value of natural gas is expected to be only 24.4%. From the power perspective, the average per-unit cost (PUC) of electrical power is estimated to span $15–19,000/kWe (depending on site-specific installation, fuel, and other costs), while the average PUC of electrical and HR power is $7,000–9,000/kW. Regarding energy, the average PUC of electrical energy is $0.38–$0.46/kilowatt-hour-electric, while the average PUC of electrical and HR energy is $0.18–$0.23/kWh. GHG emissions were estimated to decrease by one-third after replacing a conventional system with a CHP FCS. GHG mitigation costs were also proportional to changes in GHG emissions. Estimated human health costs from air pollution emissions decreased by a factor of 1000 with changing to CHP FCS. Reported for the first time here is the derivation of the PUCs of power and energy for a CHP device from both standard and management accounting (MA) perspectives. Results show that the average PUC of combined electrical and HR power is equal to the average PUC of electric power applying an MA approach, and also equal to the average PUC of HR power applying an MA approach. Similar relations hold for the average PUC of energy. Results presented here demonstrate the value of using the equations herein for economic analyses of CHP systems to represent the average PUC of electrical power, HR power, or both, and for energy.

Greenwashed energy transitions: Are US cities accounting for the life cycle greenhouse gas emissions of energy resources in climate action plans?

According to the US Department of Energy, succinic acid (SA) is a top platform chemical that can be produced from biomass. Bread waste, which has high starch content, is the second most wasted food in the UK and can serve as a potential low cost feedstock for the production of SA. This work evaluates the environmental performance of a proposed biorefinery concept for SA production by fermentation of waste bread using a cradle-to-factory gate life cycle assessment approach. The performance was assessed in terms of greenhouse gas (GHG) emissions and non-renewable energy use (NREU). Waste bread fermentation demonstrated a better environmental profile compared to the fossil-based system, however, GHG emissions were about 50% higher as compared to processes using other biomass feedstocks such as corn wet mill or sorghum grains. NREU for fermentative SA production using waste bread was significantly lower (~ 46%) than fossil-based system and about the same as that of established biomass-based processes, thus proving the great potential of waste bread as a valuable feedstock for bioproduction of useful chemicals. The results show that steam and heating oil used in the process were the biggest contributors to the NREU and GHG emissions. Sensitivity analyses highlighted the importance of the solid biomass waste generated in the process which can potentially be used as fish feed. The LCA analysis can be used for targeted optimization of SA production from bread waste, thereby enabling the utilization of an otherwise waste stream and leading to the establishment of a circular economy.

Solar Thermal Trigeneration System in a Canadian Climate Multi-unit Residential Building